Unity Game Testing: iPad1, iPad2, or both?

Hello - I would like to purchase an iPad to start testing the Unity game I've been working on, but I'm unsure what kind of iPad to get, or if it matters at all. I would think the majority of iPad owners still own the original, so it makes sense to pick that one up. My concern in picking up the iPad2 is that the increased/speed or power won't highlight any potential problems my game may have running on the original iPad.

So, does anyone know if there is a big enough difference between the two models to be worried about this, or does it not matter at all?

The graphics are significantly faster on the iPad 2. Ideally, if you want to test properly you need both, though if it runs well on an iPad 1 then by default it will run fine on an iPad 2.

You need both, or you risk crashes and one-star reviews. I had an app run fine on iPAD2, but crash on iPAD1, if plenty of apps are sleeping in the background. Also, fps was so slow on iPAD1, I had to fine tune the game to make it acceptable.